1. Field of the Invention
The present invention relates to a male terminal fitting and to a production method for such a male terminal fitting.
2. Description of the Related Art
Male terminal fittings often are formed by stamping a plate-shaped metallic terminal material of a specified thickness and then bending the stamped material into a specified shape. The male terminal fitting of this type typically has the leading end of the terminal material folded back to form a thick tab, as shown, for example, in Japanese Unexamined Patent Publication No. 11-224701. A tab formed in this manner can be twice as thick as the terminal material.
The specified thickness of the tab of the male terminal fitting often is based on characteristics or design limitations of the female terminal fitting. The thickness of the terminal material for the male terminal fitting then is selected as half the specified thickness of the tab.
The male terminal fitting may also have a barrel that is configured to be crimped by an applicator into connection with a wire. Applicators have a range of material thickness that can be crimped. Attempts may be made to reduce production costs by reducing the number of kinds of applicators. However, the number of kinds of applicators that is required is determined by range of material thicknesses that is required, and the prior art terminal design required the range of material thicknesses to be dependent directly on the range of specified thicknesses of the tab. As a result, the prior art male terminal fitting design impeded the ability to reduce the number of types of applicators for crimping. Furthermore, a specification for a thick male terminal tab could complicate the crimping of the terminal fitting to the wire.
In view of the above situation, an object of the present invention is to form a tab having a desired thickness without being influenced by the thickness of a terminal material.
The invention is directed to a male terminal fitting made of a plate-shaped metallic terminal material and having a tab formed by folding back or bending the terminal material. The tab comprises a base and at least one substantially U-shaped turning portion. At least one overlapping portion is connected to the base via the turning portion and substantially faces the base. At least one raising portion extends from an end of the overlapping portion and is held substantially in contact with the base. Thus, at least one space is defined between the base, the turning portion, the overlapping portion and the raising portion. The thickness of the tab can be set at a desired value regardless of the thickness of the terminal material by changing a curvature of the turning portion and a projecting distance of the raising portion.
The overlapping portion and the base may be substantially flat and substantially parallel. Additionally, the raising portion may extend from the overlapping portion substantially at right angles and may be held in contact with the base.
Bending a narrow strip adjacent to an edge is difficult and has limits. Thus efforts to reduce the projecting distance of the raising portion are limited. However, a contact area of the base with the raising portion may be recessed to form a receiving portion that may be stepped from and substantially parallel to the remaining surface area of the base that faces into the space of the tab. The recessed receiving portion is formed in the contact area of the base with the raising portion. Therefore, the projecting distance of the raising portion can be acceptably large without increasing the overall thickness of the tab.
The contact area of the base with the raising portion may be formed into a receiving surface that is slanted with respect to the remaining area of the base. Additionally, a projecting end of the raising portion may be formed into a contact surface that is slanted and substantially parallel to the receiving surface or complementary to the corresponding receiving surface.
A variation of the projecting distance of the raising portion due to a tolerance can be taken up by bringing the contact surface into sliding contact with the receiving surface. Therefore, the thickness of the tab can be adjusted with high accuracy.
The base may comprise a mating raising portion that projects from the base and contacts the raising portion on the overlapping portion.
The invention also is directed to a method for producing a male terminal fitting. The method comprises providing a substantially plate-shaped metallic terminal material and forming a tab by folding back the terminal material. The folding step comprises bending the terminal material to form a base, at least one substantially U-shaped turning portion, at least one overlapping portion and at least one raising portion. The overlapping portion is connected to the base via the turning portion and substantially faces the base. The raising portion extends from an end of the overlapping portion and contacts the base.
The method may further comprise a step of recessing and/or slanting the base to form a receiving portion for the raising portion.
Additionally, the raising portion may be formed with a shape substantially complementary to the shape of the receiving portion.
These and other objects, features and advantages of the present invention will become apparent upon reading of the following detailed description of preferred embodiments and accompanying drawings. It should be understood that even though embodiments are separately described, single features thereof may be combined to additional embodiments.